Low yellowing scorch inhibitor composition

Abstract

A scorch inhibitor composition for use an additive in the manufacture of polyurethane foams is based on a derivatized phenol, 4-tertbutyl catechol, and optionally, phenothiazine. The derivatized phenol is a di-tert-butyl phenol, preferably a 2,6 tert-butyl phenol substituted at least at the 4-position with an aliphatic, aromatic or aliphatic-aromatic moiety, of C2 or greater. Preferably, the phenol is a liquid, and is chosen from among 2,6 di-tert-butyl-4-isobutyl phenol; 2,6 di-tert-butyl-4-nonyl phenol; and benzenepropanoic acid, 3,5-bis (1,1-dimethyl-ethyl)-4-hydroxy-.C7-C9 branched alkyl esters. The phenol may optionally possess combinations of heteroatoms, such as O, N, P or S, and may be dimerized.

What is claimed is:  
     
       1. A scorch inhibitor composition for use an additive in the manufacture of polyurethane foams, comprising: 
       a derivatized di-tert-butyl phenol, substituted with an aromatic, aliphatic or aromatic-aliphatic moiety of C 2  or greater, the moiety optionally possessing combinations of heteroatoms, which optionally may be dimerized,  
       4-tertbutyl catechol, and  
       optionally, phenothiazine.  
     
     
       2. The composition of claims  1 , wherein the heteroatoms are one or more chosen from the group consisting of N, O, S and P. 
     
     
       3. The composition of  claim 1 , wherein the phenol is chosen from the group consisting of 2,2′-thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate; 4,4′-thio-bis-(2-t-butyl-5-methyl-phenol; and 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl) hydrazine. 
     
     
       4. The composition of  claim 1 , wherein the phenol is 2,5-di-t-amyl-hydroquinone. 
     
     
       5. The composition of  claim 1 , wherein the phenol is a 2,6-di-tert-butyl phenol derivative or a 2,4-di-tert-butyl phenol derivative. 
     
     
       6. The composition of  claim 5 , wherein the phenol is 2,6 di-tert-butyl-4-isobutyl phenol. 
     
     
       7. The composition of  claim 5 , wherein the phenol is 2,6 di-tert-butyl-4-nonyl phenol. 
     
     
       8. The composition of  claim 5 , wherein the phenol is a liquid phenol. 
     
     
       9. The composition of  claim 8 , wherein the phenol is chosen from the group consisting of 2,6 di-tert-butyl-4-isobutyl phenol; 2,6 di-tert-butyl-4-nonyl phenol; and benzenepropanoic acid, 3,5-bis (1,1-dimethyl-ethyl)-4-hydroxy-.C7-C9 branched alkyl esters. 
     
     
       10. The composition of  claim 9 , comprising the following in weight percent: 
       derivatized phenol at 45-95%  
       tert-butyl-catechol at 5-55%  
       phenothiazine at 0-2%.  
     
     
       11. The composition of  claim 10 , comprising the following in weight percent: 
       derivatized phenol at 65-75%  
       tert-butyl-catechol at 22-35%  
       phenothiazine at 0-0.75%.  
     
     
       12. The composition of  claim 11 , comprising the following in weight percent: 
       derivatized phenol at about 66.5%  
       tert-butyl-catechol at about 33%  
       phenothiazine at about 0.5%.  
     
     
       13. The composition of  claim 5 , comprising the following in weight percent: 
       derivatized phenol at 45-95%  
       tert-butyl-catechol at 5-55%  
       phenothiazine at 0-2%.  
     
     
       14. The composition of  claim 13 , comprising the following in weight percent: 
       derivatized phenol at 65-75%  
       tert-butyl-catechol at 22-35%  
       phenothiazine at 0-0.75%.  
     
     
       15. The composition of  claim 14 , comprising the following in weight percent: 
       derivatized phenol at about 66.5%  
       tert-butyl-catechol at about 33%  
       phenothiazine at about 0.5%.  
     
     
       16. A polyurethane foam, comprising a scorch inhibitor composition according to any of claims  1 - 15 .